Usually the one line comes into my head first = " The door I want to enter, the one I fear the most."
The theme of "going through the door" is set, but most of the poem does not matter at this point as I recycle the thoughts through different scenarios of going through the doors of different choices with different meanings. I quickly jot down the first thoughts that come into my head, with some lines matched, and other lines by themselves. No corrections at this point, just dump my first original thoughts in random order.… and that looks like this…

Version 1… First thoughts.
The door I want to enter
The one I fear the most
I wish there were side windows
To peak at what is there
The door I want to enter,
I’ve been through there before
The door I want to enter
It has it’s up and downs
The door I want to enter
Excites my every thought
The door I want to enter
More than once postponed
The door I want to enter
I hold the key to enter
The door I want, wish, dream, that I will, to enter
The door I close behind me
The doorS I need
The doors I love to
The doors I build in
- - - - - - - - - - - -

Version 2, The Arrangement.
I then start to form quick groupings of verses, some with multiple line choices that I will choose/tweak later. The trick for me is to not discard anything at this point because the overall theme and message has not yet been determined, although it is starting to take shape. Specific editing of lines happens after this. For now, I lock in the first lines and the last and listen to the middle ones for correct flow.

The door I want to enter
the one that makes me smile
is usually the one less opened
is the one less opened
the trip that’s been a while.

The door I’d like to enter
The one I wish the each day
Is the one that includes you
Is where I still see you
Includes you in the opening
As I open the pathway

I wish there were side windows
To peak at what is there
The opening is sudden
While my dreams soon meet the where
My dreams still meet the where

The doors I need to open
Are clearly my own choice
If I’m to be the future
If I’m to see the future
I must listen to my voice

I hold the key to enter
My thoughts, my steps, my words
My words, my steps my thoughts
The excitement that awaits me
I accept the paths I bought

The door I close behind me
The one I just stepped through
Paints the ‘morrow plainly
My happiness with you.
- - - - - - - - - - - - - - - -
Version 3, Clean Up The Message.

I'm getting close as I re-read every line multiple times to learn the pace, start to configure the continuity, and the story I'm trying to tell. I clean up the lines and focus on each verse for a complete thought that builds the poem to what I am trying to say.

The door I want to enter
the one that makes me smile
is the one less opened
the trip that’s been a while.

The door I’d like to enter
The one I wish the each day
secures the path to my goals
As I open the pathway

I wish there was a peak hole
for a taste of what is there
While my dreams soon meet the where
My dreams still meet the where

The doors I need to open
Are clearly my own choice
If I’m to see the future
I must listen to my voice

I hold the key to enter
My words, my steps my thoughts
The excitement that awaits me
I accept the paths I bought

The door I close behind me
The one I just stepped through
Paints the ‘morrow plainly
My happiness with you.
- - - - - - - - - -
Version 4, The Test And The Finish.
Although some lines are really expressive and I love what they say, I am forced to disregard them as they no longer fit my final version that I am building to. I am still re-reading the lines from start to end over and over as I see the need to now move the verses in the proper order that makes the poem more of a story from start to finish. I then add the punctuation and test myself on the finished version = does it flow nicely, is there a start and beginning of a flow that feels right, did I get the message across of what I am trying to say, etc. Now I need the title… I'm done until the next one liner hits my brain to repeat the process. Remember.. this is MY process and how it works for me. Your process should be unique to you and more importantly… what works for you. .. And here is the finished version…
The Door I Want To Enter

The door I want to enter,
the one that makes me smile,
is the one less opened,
the trip that’s been a while.

The door I’d like to enter,
the one I wish each day,
secures the path to my goals,
the one that shows the way.

The doors I need to open,
are clearly my own choice.
If I’m to build the future
I must listen to my voice.

I wish there was a peak hole
for a taste of what's in there,
the door with my own preview
so my dreams can meet the where.

I hold the key to enter,
my words, my steps, my thoughts,
the excitement that awaits me
I accept the paths I bought.

The door I close behind me,
the one I just stepped through,
paints the ‘morrow plainly,
my happiness with you.